Some small fixes to tst-pipe.cc

tst-pipe.cc read a buffer after freeing it, which could have theoretically
caused segfaults (it didn't in practice, but better fix this oversight).

Also, it forgot to return a return code, so it doesn't play nicely in
a test framework like testrunner.so. I'm surprised the C++ compiler wasn't
bothered by an int main() not returning an int.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

tests/tst-pipe.cc

@@ -330,7 +330,9 @@ int main(int ac, char** av)
     report(r==1 && poller.revents == POLLOUT, "empty pipe is ready for write");
     r = fcntl(s[1], F_SETFL, O_NONBLOCK);
     report(r == 0, "set write side to nonblocking");
+    buf1 = (char*) calloc(1, TSTBUFSIZE);
     r = write(s[1], buf1, TSTBUFSIZE);
+    free(buf1);
     report(r > 0, "large write to fill pipe");
     r = fcntl(s[1], F_SETFL, 0);
     report(r == 0, "set write side to blocking");
@@ -364,6 +366,7 @@ int main(int ac, char** av)
 
 
     debug("SUMMARY: %d tests, %d failures\n", tests, fails);
+    return fails == 0 ? 0 : 1;
 }